Field of the Invention
The present invention relates to a substrate transport device that transports a substrate, a substrate processing apparatus including the substrate transport device, and a substrate transport method.
Description of Related Art
Substrate processing apparatuses are used to subject various substrates such as semiconductor substrates, substrates for liquid crystal display devices, plasma displays, optical disks, magnetic disks, magneto-optical disks, photomasks, and other substrates to various types of processing.
In such a substrate processing apparatus, in general, a single substrate is subjected to successive processes in a plurality of processing units. As such, the substrate processing apparatus is provided with a transport mechanism (substrate transport device) that transports the substrate among the plurality of processing units.
For example, a transport mechanism of a substrate processing apparatus as described in JP 2014-22589 A1 has a hand for holding a substrate. The transport mechanism is provided with a plurality of detectors. The plurality of detectors detect a plurality of portions at an outer periphery of the substrate held by the hand, respectively, whereby the position of the substrate on the hand is detected. Coordinate information indicating a position at which the substrate is received by the hand and a position at which the substrate is placed by the hand is stored for each processing unit. A reference position is set in the hand in advance. If the substrate is deviated from a predetermined position in one of the processing units, the hand of the transport mechanism receives the substrate in a state where the center of the substrate is deviated from the reference position. In this case, the deviation of the substrate from the reference position of the hand is detected based on the result of detection by the plurality of detectors before the substrate is placed in another processing unit. Based on the detected deviation, the coordinate information is corrected so as to cancel a deviation between the position of the center of the substrate to be placed by the hand in the other processing unit and a predetermined position in the other processing unit. The transport mechanism is controlled based on the corrected coordinate information. Thus, the substrate is placed at the predetermined position in the other processing unit.